well first off, before you can get into the vmax/zmax forum, lets take a look at this chart:
now, you want to be in the green area when you set voltage...the advantage of owning a vmax is that you can read your
juice delivery system's ohms in the menu system....i'm not sure how that works on a vmax, but the zmax menu system is accessed by clicking the button 3 times quickly....you should be able to look up the instruction manual for the
device online (probably best to start at the smoketech website) and figure out how to set your voltage and check resistance...once you have checked resistance, consult the chart, and shoot for the high green numbers.